Lifting jack



S. A. SNELL Nov. 22,` 1932.

LIFTING JACK Original Filed Nov.'7. 1927 su ai 9 Patented Nov. 22, 1932 UNITED STATES PATENT' OFFICE SAMUEL A. SNELL, OF TOLEDO, OHIO, ASSIGNOR TO NAGOLE, INC., 0F TOLEDO, OHIO, A CORPORATION OF OHIO LIFTIN G JACK Application led November 7, 1927, Serial No. 231,400. Renewed August 16, 1932.

This invention pertains to lifting jacks. In many situations in which a lifting jack is to be used, the height of that part of the object to be lifted against which the jack must bear, is somewhat higher than the lowest adjustment of the jack itself. Accordingly, the jack must 'be screwed up to some eX- tent before actual engagement with the object is effected. Such a situation obtains, for instance, in jacking up an automobile where the axle of the automobile stands somewhat higher than the lowest adjustment of the jack. In such a case, a considerable portion of the lifting range of the jack is wasted in idle movement, and it may be found that the length of the screw remaining is insuflicient to lift the object to the desired height. Thus,

the full lifting range of the jack is not available, except under certain particular circumstances, when the height of the object is just sufficient to permit the jack at its lowest adj ustment to be placed thereunder.

One of the objects of this invention is to provide a jack which may be adjusted to take up such idle movement without operation of the lifting element.

Another object is to provide a jack with an extension device which may be adjusted to any desirable height so as to engage the object before operating the lifting element in order that the full lifting range of the jack may be available.

nother object is to provide a jack of robust and substantial construction which shall be cheap to manufacture and durable and eilicient in service.

Further objects will appear from the following description, taken in connection with the accompanying drawing, in which- Figure 1 is a side elevation, partly in section, of a lifting ack embodying this invention;

Figure 2 is a section on line 2--2 of Figure 1;

Figure 3 is a fragmentary detail perspective view of the perforated gear which opcrates the screw; and y Figure 4 is an enlarged detail of Figure 1.

Referring to the accompanying drawing, 1 designates a casing or base, which may be constructed of pressed sheet metal so as to have a conica-l flaring lower portion 2 and a vertical cylindrical guide portion 3. The base 1 is preferably made in two half sections, each formed with reinforcing flanges 4 which 55 may be fastened -together 'by rivets 5 or other suitable fastenings. The bottom of the base is closed by a. bottom plate 6 suitably secured to the base flanges 7 by rivets or other suitable fastenings 70. Mounted upon the bottom plate 6 is a ball race 8 adapted to accommodate a ring of steel balls'9, forming aI ball thrust bearing. Resting on the bearing formed 'by the balls 9 is a gear plate 10, provided wit perforations 11 around its periph- 65 ery, the sections 12 between said perforations providing gear teeth adapted to mesh with the teeth of a pinion 13 suitably j ournaled in 'a bearing 14 'formed in the base 1 and stiffened by reinforcing flanges similar to the flanges 4. The gear plate 10 has a marginal flange 15 of conical form adapted to fit the fiared bottom 2 of the base. Fixed to the center of the gear plate 10 is a lifting screw 16. The bore of the gear 10 is provided with 75 teeth 30. The gear is case hardened and forced onto the sha-nk 31 of the screw 16, whereby the teeth 30 are caused to bite into the material of said shank so as to secure the gear against rotation thereon. It will be seen that by turning the gear 13 by any suitable means, such as a crank 171emovably seated in a socket in said gear, the gear 10 will be driven so as to turn the screw 16. This screw turns on the ball bearings 9 85 so that friction is reduced to a minimum.

Working on the screw 16 is a nut 18. Fixed to the nut 18 so as to be carried thereby, is a tube or sleeve 19. The tube 19 may be constructed of sheet metal bent to tubular form and is fitted to slide vertically within the guide portion 3 of the base `l. The tube 19 has formed therein, by pressing or otherwise, a longitudinal indentation or groove 20. One .of the halves of the base 1 has a 95 tongue or key 2l struck inwardly therefrom so as to engage the groove 20 in order to prevent rotation of said tube in the guide 3. It Will be seen that when the screw 16 is rotated the tube 19 and thenut 18 will be 100 prevented from rotating, and the nut will be fed upwardly along the screw, carrying with it the tube 19.

Mounted in the upper end of the tube '19 5 is an extension tu'be 22. This tube is fitted to slide telescopically within the tube 19 so that it may be adjusted relatively thereto. It carries at its upper end an abutment 23 adapted to engage the object to be lifted.

p The tube 22 is provided with an indentation y justed position relatively to the tube 19, the

former tube is provided with a series of per- 25 forations26 at intervals therealong. These perforations are adapted to receive a stop pin 27. The perforations 26 are preferably elongated in a horizontal direction, as illustrated in Figure 2, and the pin 27 is flat so as to provide an extended bearing where it rests upon the upper end of the tube 19.

The pin 27 thus inserted in the perforations 26 supports the extension 22 in any one of 'a series of extended positions. lA chain 28 mayr be provided to secure the pin 27 to the jac so as to prevent its getting lost.

v In the use of this jack, the same may be placed in position with its screw adjusted to its lowermost adjustment. If the jack is 40 then too short to engage the object, the extension 22 may be pulled out` a sucientex- 'tent and the pin 27 inserted in the appropriate perforations 26 so Ias to support the extension in its adjusted position. The screw may now be operated to lift the object, and the full lifting range of the jack will be available so that the object may be lifted through the full extent of such range at one opera.- tion.

It will be seen, therefore, that this jack provides a simple and rugged construction for a lifting j ack and one which is adjustable to engage objects of different heights so that the full lifting range of the ljack may be efi fective. It isthus unnecessary to place the jack on a block or make use of a similar expedient when the object is high, and the d'anger of slippage and consequent accident is thereby avoided.

It will be noted that thefgear 10 is supported clear of the bottom 6 by the ball bearing 9. The flared rim 15 of the gear fits the flared portion-2 of the casing and is guided thereby so as to insure smooth running. This 05 action is, therefore, practically frictionless.

The gear 10, being case hardened and resting on the balls 9 close to the inner bore thereof, the weight of the load will be concentrated on the points of Contact of the balls with the plate. This tends to cause deformation of the plate as indicated at 32 in Figure 4. Such deformation tends to cause spreading of the material outwardly from the points of contact of the balls. Since the outer portion of the plate 10 resists such movement of material in that direction, the result will be to `crowd the' material inwardly so as to reducel the bore of the gearV l10. This action crowds the teeth 30 against the shank with greater force the greater the load lifted by the ack, and thus insures 'against slippage at heavy loads.

It is obvious that various changes may be made, within the scope of the appended claims, in the details of construction without departing from the spirit of this invention; it is, therefore, to be understood that this invention is not limited to the specific details shown and described.

Having thus described the invention, what is claimed is:

1. A lifting ack, comprising, a sheet metal casing consisting of formed half sections,

,each having flanges extending therealong,

said sections beingl secured together through said flanges to provide a reinforced tubular guide, each of said sections having a lateral extension formed to provide a cylindrical tubular bearing portion having a reinforcing flange therealong, said bearing portions of said half-sections forming together a bearing, a lifting element guided for movement in said casing, and a driving element mounted for rotation in said bearing.

2. A lifting jack, comprising, a gear hav'- ing an opening provided with inwardly extending teeth, a screw having a plug pressed into said opening so as to be secure by said teeth, and a thrust bearing for said gear around said opening.

3. A lifting jack, comprising, a caslng, a retable lifting element therein, a gear havingan opening provided with inwardly extending teeth, a plug on said lifting element pressed into said opening to be secured by said teeth, the portion of l,said gear surrounding said opening forming a ball race, and a ball bearing engaging said race-and supporting said liftin element.

4. A lifting Jack, comprising, a sheet-metal' casing formed in matching half-sections, each having flanges extending therealong, said sections being secured together thru said flanges to provide a reinforced tubular guide having aiiaring base portion, each` of said sections having a lateral extension formed to provide a cylindrical tubular bearing portion, said bearing portions of said half-sections forming together a bearing positioned radially of said casing, a lifting element casing, certain portions of said casing having guided for movement in said casing, a gear -connected to drive said lifting element and fitted to said flaring base portion to be guided thereby, and a driving pinion engaging said gear and having a shank journaled in said radial bearing.

- 5. A lifting jack comprising a sheet metal flanges;v means for securing said llanges together to provide a re-enforced tubular guide; an integral lateral extension formed on said casing to provide a cylindrical tubular bearing; a lifting element guided for movement in said casing, and a driving element for said lifting elementmounted for anges; means for securing said anges together to provide a re-enforced tubular guide; a lateral extension integrally formed on said casing to provide a cylindrical tubular bearing; a lifting element disposed in said tubular guide; a driven gear enclosed within the casing, and a driving gear enmeshing with said driven gear and journalled for rotation in thecylindrical tubular bearing.

8. A lifting ack comprising a sheet metal casing having a tubular guide portion; a

lateral extension integrally formed on said' casing to provide a cylindrical tubular bearing; a lifting screw adapted for longitudinal movement in said tubular guide; a driven gear cooperating with said lifting screw; and enclosed Within said casing, and a driving gear enmeshing with said driven gear and mounted for rotation in the cylindrical tubular bearing.

9. A lift-ing jack comprising a sheet metal casing having atubular guide portion; a lateral extension integrally formed on said casing to provide a cylindrical tubular bearing; a lifting screw adapted' for longitudinal movement in said tubular guide; a driven gear cooperating with said lifting screw; a driving gear` cooperating with said driven gear and mounted for rotation in said cylindrical tubular bearing, said gears being enclosed within said Casin v In testimony whereof alix my signature this 5th day of October, 1927.

SAMUEL A. SNELL. 

